New Delhi: Pakistan has in-principle agreed to allow a team of Indian investigators to go to that country to examine the evidence collected against arrested LeT commander Zakiur Rehman Lakhvi and six others, who are being tried in 26/11 terror attack case there.

However, Islamabad is yet to give dates for the visit of National Investigation team, which will also try to understand why the Pakistani court was not ready to accept the evidence collected by a Pakistani judicial commission during its visit to India in March.

"Pakistan has in-principle agreed to allow the NIA team to visit that country. We have already sent a formal request through the Ministry of External Affairs and we are awaiting intimation about the dates," a Home Ministry official said.

Frustrated over the long delay in the trial against Lakhvi and six others in a Rawalpindi court, India had conveyed to Pakistan that it wanted to send the team to examine the material evidence collected against arrested 26/11 terror attack prime accused.

The issue was first raised when Home Minister Sushilkumar Shinde met his Pakistani counterpart Rehman Malik on the sidelines of the SAARC ministerial meeting in Maldives last month.

New Delhi also wants to understand why the Pakistani court was not ready to acknowledge the international convention of accepting a bilateral treaty between two sovereign nations.

The eight-member Pakistani judicial commission had visited India following a bilateral agreement which said the commission would not quiz the magistrate, who had recorded the statement of 26/11 lone surviving terrorist Ajmal Kasab, the Investigating Officer of the case and two doctors who conducted the postmortem of slain terrorists.

However, after the Pakistani court dealing with the 26/11 case had said that evidence collected by the commission during its visit to India in March had no "evidential value" to punish those involved in the Mumbai terror attack, Islamabad had asked New Delhi to allow its panel to visit Mumbai again.

India will allow the second visit of the Pakistani panel only after the visit of the NIA team. Shinde had told Malik that the NIA team should be allowed to visit Pakistan to examine the evidence collected by the Federal Investigation Agency (FIA) of Pakistan and understand the reasons for the inordinate delay in convicting the prime accused.

NIA is also likely to find out from FIA why action could not be taken against LeT founder and terror mastermind Hafiz Sayeed and the problem in handing over the voice samples of those who were involved in planning and executing the worst ever terror attack in India that claimed 166 lives.